This invention relates generally to the navigation of a moving vehicle. In particular, this invention relates to a method and system of providing multiple beginning instructions for navigating the vehicle from a route generator.
Currently it is possible to navigate a vehicle, such as a car, using a database onboard the car that includes directions and coordinates for various locations. For example, the database may include existing directions and coordinates for the entire United States. Such a navigation system is sometimes called an autonomous navigation system.
In existing autonomous navigation systems, the directions for navigating the vehicle are generated by a processor, which is also on board the vehicle. The processor accesses the database and calculates directions based on the current location of the vehicle and the intended destination. Autonomous navigation systems are typically very expensive. Additionally, these autonomous systems become easily outdated as the coordinates and locations and points of interest stored in the database become outdated. One alternative to autonomous navigation systems is to communicate with a server that can calculate a navigation route and transmit it to the vehicle. Typically, in such a server-based system, the current location of the vehicle is determined by the server using Global Positioning Systems and software. Dead reckoning systems such as gyroscopes or the use of vehicle speed pulses may also be used to help determine the current location of the vehicle. The destination is also indicated to the server, for example, by user-input. Then, the server generates a route based on these two points.
This server-based process may be very time consuming. Sometimes, the process of downloading the maneuver list from the vehicle""s current location to the destination may take a significant amount of time if the maneuver list is extensive. This may result in missed maneuvers or invalid routes as the vehicle continues beyond the original location upon which the maneuver lists were based. For example, a vehicle may pass the first maneuver before the instruction to navigate the first maneuver is downloaded. Moreover, current server-based navigation systems do not provide off-route detection, i.e. an indication that the vehicle has gone off the route indicated by the maneuver list. Additionally, current server-based navigation systems do not provide off-route correction. That is, because the database is not on board, there is a time lag between the time when a vehicle goes off-route and when the vehicle receives new maneuver instructions. This time lag may occur, for example, because the vehicle has to send a new request for a corrected route to the server based on a new current location.
It would be desirable therefore to provide a method for generating instructions for navigating a moving vehicle that overcomes the above.
One aspect of the present invention provides a method of generating navigation instructions for a vehicle. A destination of the vehicle is received at a route generation application. A maneuver list comprising a plurality of navigation instructions is calculated based on a current location of the vehicle and the destination. A distance threshold is determined based on the current location of the vehicle and the destination. The navigation instructions located within the distance threshold are determined and transmitted from the route generation application to the vehicle. The navigation instructions located within the distance threshold are executed at the vehicle. At least one remaining maneuver may be transmitted from the route generation application while the vehicle executes the navigation instructions located within the distance threshold. The at least one remaining maneuver may also be executed at the vehicle. The distance threshold may be based on a speed of the vehicle or on road density information. The maneuver list may also be based on a speed of the vehicle or on road density information.
Another aspect of the present invention provides a navigation system including at least one route generation application, which calculates a maneuver list comprising a plurality of navigation instructions. The route generation application further determines a distance threshold and preliminary navigation instructions that lie within the distance threshold. The system also includes at least one service manager in communication with the route generation application and a vehicle, which is operatively adapted to execute the navigation instructions. The service manager may transmit the preliminary navigation instructions from the route generation application to the vehicle.
The system also includes at least one database in communication with the route generation application, the database comprising location coordinates. The system also includes at least one navigation interface in communication with the vehicle operatively adapted to receive the navigation instructions. The system also includes at least one communication interface in communication with the vehicle, the communication interface operatively adapted to transmit information from the vehicle.
Another aspect of the present invention provides a computer usable medium including a program for generating navigation instructions for a vehicle. The program includes computer program code that receives a destination of the vehicle and computer program code that calculates a list of navigation instructions based on a current location of the vehicle and the destination. The program also includes computer program code that determines a distance threshold. The program also includes computer program code that determines navigation instructions located within the distance threshold and transmits these instructions to the vehicle. The program also includes computer program code that executes the navigation instructions located within the distance threshold at the vehicle. The program also includes computer program code that transmits at least one remaining maneuver to the vehicle while the vehicle executes the navigation instructions located within the distance threshold. The program also includes computer program code that executes the at least one remaining maneuver at the vehicle. The program also includes computer program code that determines the distance threshold based on a speed of the vehicle or on road density information. The program also includes computer program code that determines the navigation instructions based on a speed of the vehicle or on road density information.
Another aspect of the present invention provides a system of generating navigation instructions for a vehicle. The system may include means for receiving a destination of the vehicle at a route generation application, means for calculating a maneuver list based on a current location of the vehicle and the destination, the maneuver list comprising a plurality of navigation instructions and means for determining a distance threshold based on the current location of the vehicle and the destination. The system may also include means for determining navigation instructions located within the distance threshold and means for transmitting the navigation instructions located within the distance threshold from the route generation application to the vehicle.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.